1 HOMEOSTASIS: The process in
which the body's internal
conditions are regulated
1.1 Sugar Control
1.1.1 Insulin: This is the hormone produced by the
pancreas that regulates glucose levels in the
22.214.171.124 NEGATIVE FEEDBACK LOOP: A negative
feedback control system responds when
conditions change from the ideal or set point
and returns conditions to this set point. There
is a continuous cycle of events in negative
1.2 Water Control
1.2.1 THE NEPHRON:
126.96.36.199 ULTRAFILTRATION: The process that occurs at the
barrier between the blood and the filtrate in the
bowman's capsule in the kidneys
188.8.131.52.1 BOWMAN'S CAPSULE: It is a
hollow cup-like sac at the
start of the nephron.
184.108.40.206.1.1 GLOMERULUS: This is a ball of blood
capillaries in the Bowman's capsule.
This is where the blood is filtered. The
pressure in the glomerulus is very
high in order to force all the small
molecules through the basment
220.127.116.11.1.1.1 BASEMENT MEMBRANE: This
membrane is located in the
glomerulus between the capillary
wall and the wall of the capsule.
These act like a filter which allows
only small molecules to pass
18.104.22.168 SELECTIVE REABSORBTION: The process in
which only required molecules are allowed
back into the blood stream.
22.214.171.124.1 DISTAL CONVOLUTED TUBULE: This is where the final
adjustments are made. Here selective reabsorbtion
takes place allowing for small adjustments to be
make between the presence of potassium and
126.96.36.199.2 PROXIMAL CONVOLUTED TUBULE: This
is where glucose, water, salts and
amino acids are reabsorbed back into
188.8.131.52 LOOP OF HENLE:
184.108.40.206.1 DESCENDING LIMB: This is the area which is
only permeable to nutrients and salts but
not to water. This helps to concentrate the
220.127.116.11.2 ASCENDING LIMB: This is the area of
the loop of henle which is permeable
to water but not other nutrients. The
water is then reabsorbed into the loop
of henle through active transport.
1.2.2 ANTiDIURETIC HORMONE (ADH): It is
released by the pituitary gland in the
brain near the hypothalamus. This
hormone's function is to prevent the
production of dilute urine.
1.3.1 TOO HOT
18.104.22.168 SWEATING: sweat glands
in the skin release more
sweat when we get too
hot. This evaporates,
removing heat energy
from the skin.
22.214.171.124 VASODILATION: Blood
vessels leading to the skin
capillaries become wider
(dilate) allowing more
blood to flow through the
skin, and more heat to be
1.3.2 TOO COLD
126.96.36.199 MUSCLE CONTRACTION: muscles
contract rapidly and we shiver when
we're cold. These contractions need
energy from respiration, and some
of this is released as heat.
188.8.131.52 VASOCONSTRICTIONS -
blood vessels leading to the
skin capillaries become
narrower (constrict) letting
less blood flow through the
skin and conserving heat in
184.108.40.206 The hairs on the skin also help to control body temperature.
The hairs trap a layer of air above the skin, which helps to
insulate the skin against heat loss
1.3.3 EPIDERMIS: This is the first layer
of the skin and consists of the
dead cells that stop water loss.
1.3.4 HYPODERMIS: This is the third and
fattiest layer of the skin. It
insulates the body against heat
loss and is a store for energy.
1.3.5 DERMIS: This is the middle layer of the skin which
contains the sensory receptors and is the location of the
sweat glans as well as hair follicles and many small
2 EXCRETION: It is the process by
which waste products of
metabolism are removed from
2.1 NITROGENOUS WASTE: These are
waste substances that contain the
element nitrogen. Example: Urea and
2.2 THE URINARY SYSTEM
2.2.1 THE BLADDER: A muscular
bag that stores urine.
220.127.116.11 URETHRA: A tube connected to the
bladder which leads to the outside.
18.104.22.168.1 SPHINCTERS: The are two ring-like muscles on
the wall of the urethra. They contract to close
the urethra and hold back the urine. The lower
sphincter muscle is constantly controlled while
the upper one is involuntary - it automatically
relaxes when the bladder is full
22.214.171.124 URETERS: The two tubes from which urine
passes out of the kidneys and into the
2.2.2 THE KIDNEYS: The organ that
removes excess organic molecules
from the blood
126.96.36.199 THE CORTEX: This is the
darker outer region of the
188.8.131.52 THE NEPHRON:
184.108.40.206 THE MEDULLA: This is
the middle layer of the
220.127.116.11.1 THE PYRAMIDS: These are the bulges that
point inwards towards the concave side of the
18.104.22.168.1.1 PELVIS: This is where the urine is emptied out by
the pyramid through the medulla.
22.214.171.124.1.1.1 URETERS: The two tubes from which urine
passes out of the kidneys and into the
126.96.36.199 RENAL ARTERY: This is
the artery that supplies
blood to both kidneys.
This leads straight from
the body's main artery
i.e. the Aorta.
188.8.131.52 RENAL VEIN: The 'clean'
blood passes out
through each renal vein
to the main vein i.e. the